postmark-mcp, the first malicious MCP server on npm

What happened (also listed in 4)

• v1.0.16 silently BCC’d every email sent through the tool to the attacker. About 1,500 weekly downloads.

Sources

• https://www.koi.ai/blog/postmark-mcp-npm-malicious-backdoor-email-theft

This is a brief: a short, sourced summary from our incident tracking. Full advisories add commands to check whether you are affected.